1. Field of the Invention
This invention relates to a dressing for transporting exudates and other fluids away from a wound and a method of manufacturing such a dressing.
2. Discussion of Prior Art
In the field of wound dressings, for example, with absorbent wound dressings or surgical drains, different types of absorbent fabrics are used to absorb exudates emanating from a wound bed. One of the problems with many absorbent fabrics is that they tend to stick to the wound. This can cause the healing wound to be disturbed on removal of the dressing and furthermore, surface fibres from the dressing may come off and be left in the wound. Another problem is that the absorbed exudate is transported along the fabric and may come into contact with other non-infected parts of the wound that the dressing covers; this can cause infection of these areas.
There is therefore a desire in the field of wound dressings to provide a dressing with a high absorbency and a high rate of transportation of exudate away from a wound bed, while reducing any risk of reinfection of the wound caused by the spreading of exudate across non-infected areas of the wound. There is also a desire to provide a dressing that does not “stick” to the wound, whilst insulating and maintaining a moist environment for the wound.
One known way of addressing the above problems is to use perforated plastic films and laminates between the wound dressing and the wound bed. These films help reduce the adhesion of the dressing and the danger of exudates that are transported within the dressing contacting non-infected parts of the wound bed. These films, have the disadvantage, however, of hindering the absorbency rate of the exudate, as the perforations in the film are not sufficient to maximise absorbency. This may cause the exudate to remain on the wound site for longer. Another drawback with plastic films is that they are often less flexible and not as soft as the absorbent fabric. This can lead to the dressing being uncomfortable or painful when applied to a wound. It can also lead to problems for nursing staff when they try to cut the fabric for the wounds into complicated shapes to cover, for example, mobile joints. The plastic films are also fragile and easily damaged. This can lead to the absorbent fabric contacting the wound directly in certain places, with the risk of reinfection and sticking that this entails.
GB-A-1130857 discloses a dressing comprising a plurality of layers needle punched together. The outer wound contacting layer comprises a batt of polypropylene fibres produced by a carding machine, this is needled to an absorptive cellulose layer or cotton wadding layer which in turn is attached to a rayon layer. The surface of the polypropylene layer is heat treated.U.S. Pat. No. 4,211,227 discloses a nonwoven surgical sponge material having an inner core of rayon and polyester mix and a pair of outer layers of polyester fibres. The material is bonded by passing it through heated rollers.GB-A-2302669 discloses a dressing having two outer fibre batts needle punched to an inner screen formed of 80% polyester and 20% cotton yarns.